Virtualization includes creating one or more guest machines based on a host machine. The host machine includes physical hardware of a computing system and each guest machine includes a respective virtual machine (VM). A VM is an emulation of the computer system and provides functionalities of the physical hardware. A virtual machine monitor (VMM) (e.g., hypervisor) creates VMs based on the physical hardware and manages the VMs. In managing VMs, a VMM may have the ability to access or modify memory of the VMs.